Numerous methods exist for creating, transmitting and translating electrical signals corresponding to visual images. These methods of creating and manipulating video signals have, over the years, been developed in order to correspond with technology for electronically capturing visual images and reproducing them at another site or in a different medium. A variety of different standards have been created in order to achieve some predictability in this field, but these standards differ widely throughout the world due to differences in equipment and historical perspective. Color signals are considerably more complex than black/white and produce additional complications.
One result of the variety of different signal encoding and processing systems and standards has been the necessity for devices to translate a given signal from one signal scheme to another without substantial loss of resulting picture quality. Some examples of various methods and devices which have been utilized for this purpose are illustrated in U.S. Pat. Nos. 3,946,432, issued to A. Goldberg et al.; 4,266,241, issued to B. Hjortzberg: 4,227,204 issued to J. Rossi: 4,739,313, issued to M. Oudshoorn et al.; and 4,766,484 issued to J. Clayton et al.
Although a number of various techniques have been developed for translating certain types of input signals to certain types of outputs there remain gaps in the technology. Various commercial devices exist for translating specific inputs to specific outputs. Devices such as those described in the Oudshoorn et al patent are intended for use in converting a standard composite video signal for display on a computer type monitor which utilizes RGB signals. However, no products or methods are known to the inventor for converting computer generated RGB inputs for encoding for display in a variety of different display signal modes. The present invention is intended to fill that gap.
A common problem encountered in video signal processing apparatus is the degradation of the output signal quality caused by the encoding and decoding processes. The above cited patents, in addition to various commercial devices and techniques, reflect a number of different attempts to maximize the picture quality which can be derived as a result of the video output signal generated thereby. However, due to various inherent difficulties, no completely successful and economically feasible methods have yet been devised.